B44066S

Capacitor contactors, B44066S series, 12.5 … 100 kvar · EPCOS AG / TDK Electronics

When a capacitor is switched onto an AC network the result is a resonant circuit, and the inrush current can reach a multiple of the rated current — worse still when the step is switched in parallel with others already on the line and the short-circuit power at that point is high. The B44066S series answers that: these are contactors built for utilization category AC-6b, the switching of three-phase capacitors, not for motor duty. Leading contacts with damping resistors close before the main contacts and pre-charge the capacitor, so the current peak never forms. The panel gains twice over — the voltage sag and the transients that a hard connection would produce are avoided, and the main contacts and the capacitors themselves last considerably longer. The series runs from 12.5 to 100 kvar at 400 V, up to 148 kvar at 690 V, across eight frames. Epkom holds the three smallest — S1810, S2410 and S3210 — which cover the step sizes most low-voltage compensation panels are built from; the larger frames are available to order. All types are three-pole with one NO auxiliary contact, with the damping resistors tamper-proof and protected.